Telephone-exchange system.



L. H.JOHNSON.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JUNE 7. 1915.

1,291,866., Patented Apr. 10, 1917.

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@QZ W M L ew/Lsh. Johnson Affy.

ENE ETATEE PATEN FTEE.

LEWIS HOWES JOHNSON, OF BLOOMFIELD, NEVJ JERSEY, ASSIGNOB, BY MESNE ASSIGN- MENTS, I'O WESTERN ELECTRIC COMPANY, INCORPORATED,

NEW YORK.

A CORPORATION OF TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

Patented Apr. 10, 1917.

Application filed June 7, 1915. Serial No. 32,684.

To all whom it mag concern Be it known that I, LEWIS Howns JOHN- soN, a citizen of the United States, residing at Bloomfield, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone ex change systems, and more particularly to such systems of central energy type.

An object of this invention is to provide improved means for determining the volume of business of a central office.

In accordance with this invention ther is provided at each operators position a registering device, which is operative when the answering end of the link circuit is connected to a calling telephone line. Apparatus associated with the answering end of the link circuit is actuated when the answering end of the link circuit is connected with the calling line to condition for operation a sec ond registering device, which is thereafter operated upon the connection of the calling end of the link circuit with another telephone line. Both registering devices are disconnected from the link, circuit as soon as the second registering device operates.

The first mentioned registering device is for the purpose of recording the number of calls answered by the operator. The second registering device is for the purpose of recording the number 01'' connections c0mpleted by an operator.

For a more complete understanding of this invention reference is made to the accompanying drawing, which shows one embodiment of the invention and in which all apparatus is shown in its normal and unactuated condition. There is shown in the drawing a telephone exchange system comprising the usual subscribers stations A and B whose lines terminate in a central ofice, atwhich is located a cord circuit 0 for interconnecting the lines. I

Subscriber A wishing to converse with subscriber B signals theoperator in the usual manner. The operator, answering, inserts the answering plug into a jack of the calling line, causing the operation 01 the supervisory relay 1 included in bridge of the talking stands of the cord circuit. The operation of relay 1 causes the operation of relay 2 over a circuit, which may be traced from battery 3 through contact 4; of relay 5, upper winding of relay 2, contact 6 of relay 7, contact 8 of relay 1, and answering super visory lamp 9 to ground. Relay 2 in operating causes the actuation of listening relay 10, which connects an operators telephone set across the talking stands of the cord circuit and causes the actuation of relay 11, which, in operating, causes the operation of an electromagnetic registering device 12. The circuit including the winding of relay 11 and the winding of listening relay 10 may be traced from battery 15 through the winding of relay 11, the lower winding of relay 10, contact 17 of relay 5, contact 18 and right-hand winding of relay 19, sleeve contacts of the answering plug and jack, and the winding of cutoff relay 20 to ground. The resistance of the windings of relays 10 and 11 is such that relay 19 does not receive enough current to permit its operation.

The electromagnetic registering device 12 and its associated relay 11 are common to an operators position and the registering device is for the purpose of registering all. calls answered by an operator.

Finding that subscriber A desires to be connected with subscriber B, the operator insert the calling plug into a jack of Bs line, operating the relay 5 and cutting 01f relay 25. The operation of relay 5 causes the operation of calling supervisory lamp 26, and releases listening relay 10, disconnecting the operators telephone set from the talking strands of the cord circuit. In operating, relay 5 also causes the operation of relay 27 over a circuit, which may be traced from battery 28 through both windings of relay 27, contact 29 and lower winding of relay 2, lower winding and contact 30 of relay 5, contact 18 and the right-hand winding of relay 19, sleeve contacts of the answering plug and jack, and the winding of cutoff relay 20 to ground.

The actuation of relay 27 causes the operation of an electromagnetic registering device 31, which, in operating, short-circuits the right-hand winding of relay 27, where itself through the left-hand winding. Electromagnetic registering device 31 and 1ts associated relay 27 are common to an operators position, and" the registering device 1s for the purpose of recording the number of connections completed by an operator. Relay 5,

in operating, also causes the operation of .relay 35, whlch connects'the source of ranging current 36 to Bs line to cause the operation of the signal receiving device located at substation B. Relays 37 and 39 cooperate with relay 35, in a manner well understood, to cause the disconnection of the source of ringing current 36 from Bs line when the receiver at substation B is removed from the switchhook. Upon disconnection of the source of ringing current at the called substation, supervisory relay 40 operates, thereby elfacing calling supervisory signal 26.

At the conclusion of conversation subscribers A and B restore their respective receivers to the switchhooks, causing the operation of answering and calling supervisory signals 9 and 26 which furnish disconnect signals. The operator observing the disconnect signal withdraws the answering and calling plugs from the jacks, whereupon all apparatus returns to itsnormal unactuated condition.

Should the calling subscriber A, while the cord circuit is connected to the lines of A and B, desire to signal the operator to make,

another call or for any other reason, A merelyrestores the receiver to the switchhook and then removes it therefrom. This action on the part of A' causes an interrupter 50 to be connected in circuit with the answering supervisory lamp 9, thereby causing the lamp 9 to furnish a flashlng signection of the answering end of one of the link circuitsavith a calling telephone line and the connection of the calling end thereofwith another telephone line.

2. In a telephone exchange system, telephone lines terminating at a central oflice, link circuits thereat for interconnecting said lines, a registering device common to and normally associated with the link circuits Qfor recording the number of connections completed by an operator, and a circuit for said registering device open at two points,

said circuit being closed at one point when the answering jack of one of the link circuits is connected to a calling telephone line and closed at the other point upon connection of the calling end of said link circuit with another telephone line.

3. In a telephone exchange system, telephone lines terminating at a central oflice, link circuits thereat for interconnecting said lines, a registering device common to and normally associated with the link circuits for recording the number of connections completed by an operator, electromagnetic mechanism associated with the answering end of one of the link circuits actuated upon connection of the answering end with a calling telephone line for conditioning said registering device for operation, and electromagnetic mechanism associated with the calling end of said one link circuit actuated upon connection of the calling nd with another telephone line for causing the operation of said conditioned registering device.

l. In a telephone exchange system, telephone lines terminating at a central ofiice, a link circuit thereat for interconnecting said lines, a registering device at the central oiiice for recording the number of connections completed by an operator, electromagnetic mechanism associated with the answering end of said link circuit actuated upon connection of the answering end with a calling telephone line for conditioning said registering device -for operation, electromagnetic mechanism associated with the calling end of said link circuit actuated upon connection of the calling end with another telephone line for causing the operation of said conditioned registering device, and relay mechanism actuated upon the operation of said registering device to disconnect said registering device from said link circuit.

5. In a telephone exchange system, subscribers lines terminating at a central ofiice, a link circuit thereat for interconnecting said lines, a registering device at the central oflice for recording the number of connections completed by an operator, a supervisory relay in the answering end of said link circuit controlled from a connected substation and actuated when the answering end of said link is connected to a calling line, a relay operated upon the actuation of said supervisory relay for conditioning said registering device for operation, and a relay in the calling end of said link actuated upon the connection of the calling end with another telephone line for causing the operation of said conditioned registering device.

6. In a telephone exchange system, subscribers lines terminating at a central ofiice, a link circuit thereat for interconnecting said lines, a registering device at the central office for recording the number of connections completed by an operator, a supervisory relay in the answering end of said link circuit.

controlled from a connected substation and actuated when the answering end of said link is connected to a calling line, a relay operated upon the actuation of said supervisory relay for conditioning said registering device for operation, a relay in the calling end of said link actuated upon the connection of the calling end with another telephone line for causing the operation of said conditioned registering device, and relay mechanism actuated upon the operation of said registering device to disconnect said registering device from said link circuit.

7 In a telephone exchange system, subscribers lines terminating at a central oliice, a link circuit thereat for interconnecting said lines, a registering device at the central ofiice for recording the number of calls a11- swered by an operator, electromagnetic mechanism controlled from a connected substation and actuated when the answering end of said link circuit is connected with a calling telephone line for causing the operation of said registering device, a second registering device at the central ofiice for recording the number of connections completed by an operator, said second registering device being conditioned for operation upon the operation of said electromagnetic mechanism, and a relay in the calling end of said link circuit actuated upon the connection of the calling end with another telephone line for causing the operation of said conditioned registering device.

8. In a telephone exchange system, subscribers lines terminating at a central ofiice, a link circuit thereat for interconnecting said lines, a registering device at the central oflice erator, said second registering device being conditioned for operation upon the operation of said electromagnetic mechanism, a relay in the calling end of said link circuit actuated upon the connection of the calling end with another telephone line for causing the operation of said conditioned registering device, and relay mechanism actuated upon the operation of said second registering device to disconnect both of said registering devices from said link circuit.

9. In a telephone exchange system, telephone lines terminating at a central ofiice, link circuits thereat for interconnecting the lines, a registering device common to and normally associated with the link circuits for recording the number of connections completed, a circuit for the registering device open at two points, means responsive to the connection of the answering end of one of the link circuits with a calling line for closing the circuit at one point, and means responsive to the connection of the calling end of said one link circuit with another line to close the circuit at the other point to effect the operation of the registering device. In witness whereof, I hereunto subscribe my name this 4th day of June A. D., 1915.

LEWIS HOWES JOHNSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

